Conservatoire et Jardin botaniques de la Ville de Genève
Systematics of the lichen genus Usnea Adans.
The diversity of species, the taxonomy, the chorology, the ecology and the phylogeny of Usnea species is studied, particularly in Europe, Africa, North and South America.
Taxonomy and phylogeny of the Usnea species occuring in the tropical Andes (Bolivia, Colombia, Ecuador, Peru and Venezuela) and the Galapagos Islands, through the study of morphology, anatomy, chemistry, ecology and phylogenetics.
The taxonomy of the lichen genus Usnea in Europe remains poorly known. Numerous species have been described by Josef Motyka in his monograph "Lichenum Generis Usnea Studium Monographicum" published between 1936 et 1938. Environmental conditions can strongly influence the morphology of Usnea species and several of these species are now considered as morphotypes of the same species. Numerous characters used by Motyka in his identification keys are not diagnostic and leads to misleading identifications. This project aims to revise the taxonomy of European Usnea species, by providing detailed description of the species and their full (morphological, anatomical and chemical) intra-specific variation, together with a nomenclatural revision of the synonyms.
Taxonomy and systematics of the lichen genus Usnea in North America, through the study of morphology, anatomy, chemistry, and ecology.
A world checklist of the genus Usnea (Ascomycota, Parmeliaceae) is in preparation. Data on the status of the names (accepted names, synonyms, illeg. Names, etc.), on the protolog, on the type material (locality and herbarium) will be given.